There is an electronic apparatus which is placed in a rack (cabinet) using a three-member slide rail unit. The three-member slide rail unit usually includes an outer rail which is fixed on the cabinet, a middle rail which is drawably supported by the outer rail, and an inner rail which is drawably supported by the middle rail. The electronic apparatus is usually fixed on the inner rail.
When replacing such electronic apparatuses, a user removes an electronic apparatus by drawing out each rail which constitutes a slide rail unit.
FIG. 14 is a drawing of a related art illustrating a state in which an electronic apparatus as mentioned above is removed together with an inner rail. As illustrated in FIG. 14, an electronic apparatus 10 is fixed on an inner rail 23. The inner rail 23 is drawably supported by a middle rail 22. The middle rail 22 is drawably supported by an outer rail 21, the outer rail 21 being fixed on a cabinet which is not illustrated.
FIG. 15 is a drawing of another related art illustrating a state in which an electronic apparatus 10 which is fixed on an inner rail 23 is drawn out and lifted up to be removed from the inner rail 23.
For smooth sliding, the slide rail unit illustrated in FIG. 14 has a structure in which the inner rail 23 is drawn out from the middle rail 22 after the middle rail 22 has been completely extended. Therefore, when the electronic apparatus 10 is removed from the cabinet, the inner rail 23 is required to be drawn out after the middle rail 22 has been fully drawn out. This requires a large workspace in front of the cabinet, which restricts a place for the cabinet to be installed.
Although the slide rail unit as illustrated in FIG. 15 does not require a large workspace in front of the cabinet, the electronic apparatus 10 is required to be lifted up to a high position, which is a burden to a user. When an electronic apparatus 10 is mounted again after an electronic apparatus is removed, the electronic apparatus 10 has to be mounted onto the extended inner rail 23. At this time, mounting of the electronic apparatus 10 is not easy since the inner rail 23 is subject to sway.
For example, Japanese Utility Model No. 3174031 discloses a slide rail assembly in which an engaging lock between an inner rail and a middle rail can be released, the inner rail is drawn out continuously, and a synchronizing mechanism between the middle rail and the inner rail and a positioning mechanism between the middle rail and an outer rail are connected with each other.
Japanese Unexamined Patent Application Publication No. 2011-092259 discloses a slide rail unit which can reduce a workspace required for removing a moving rail from a middle rail and which can enhance the stability of a rack.
As mentioned above, when an electronic apparatus is mounted in a cabinet using a three-member slide rail, there is a problem that a place for the cabinet to be installed is restricted since a large workspace which is required in front of the cabinet for taking out the electronic apparatus from the slide rail is required to be secured.
In the above-mentioned Japanese Utility Model No. 3174031, a large number of members having a complicated shape are required, which makes the design and manufacture thereof complicated. In the slide rail unit disclosed in the above-mentioned Japanese Unexamined Patent Application Publication No. 2011-092259, a member which prevents a middle rail from being drawn out is required to be attached to a cabinet, which takes time for installation.